nova/nova/scheduler/filters/num_instances_filter.py

69 lines
2.4 KiB
Python

# Copyright (c) 2012 OpenStack Foundation
# All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
from oslo_log import log as logging
import nova.conf
from nova.scheduler import filters
from nova.scheduler.filters import utils
LOG = logging.getLogger(__name__)
CONF = nova.conf.CONF
class NumInstancesFilter(filters.BaseHostFilter):
"""Filter out hosts with too many instances."""
RUN_ON_REBUILD = False
def _get_max_instances_per_host(self, host_state, spec_obj):
return CONF.filter_scheduler.max_instances_per_host
def host_passes(self, host_state, spec_obj):
num_instances = host_state.num_instances
max_instances = self._get_max_instances_per_host(
host_state, spec_obj)
passes = num_instances < max_instances
if not passes:
LOG.debug("%(host_state)s fails num_instances check: Max "
"instances per host is set to %(max_instances)s",
{'host_state': host_state,
'max_instances': max_instances})
return passes
class AggregateNumInstancesFilter(NumInstancesFilter):
"""AggregateNumInstancesFilter with per-aggregate the max num instances.
Fall back to global max_num_instances_per_host if no per-aggregate setting
found.
"""
def _get_max_instances_per_host(self, host_state, spec_obj):
max_instances_per_host = CONF.filter_scheduler.max_instances_per_host
aggregate_vals = utils.aggregate_values_from_key(
host_state,
'max_instances_per_host')
try:
value = utils.validate_num_values(
aggregate_vals, max_instances_per_host, cast_to=int)
except ValueError as e:
LOG.warning("Could not decode max_instances_per_host: '%s'", e)
value = max_instances_per_host
return value